Extended Data Fig. 1: Design and characterization of S sensors.
From: Engineering luminescent biosensors for point-of-care SARS-CoV-2 antibody detection
a, Annotated depiction of the SARS-CoV-2 Spike protein. The S sensors were developed using only the S-RBD domain (aa 328–533, PDB: 6W41) shown in pink. b, Structure of the S-RBD domain shows the N and C termini locate in close proximity. c, d, Modeling of c, ACE2-competitive antibody C105 (PDB: 6XCN) binding to S-RBD-SmBiT/LgBiT sensors, and d, CR3022 (PDB: 6W41) binding to S-RBD-SmBiT/LgBiT sensors. Modeling and distance measurements were performed with PDB 6XCN, 6W41, 1N8Z, 5IBO and 5D6D in PyMOL. e, Yield of the 5 Spike-NanoBiT sensor fusions. The Spike LgBiT sensors were made with 5aa, 15aa, and 25aa Glycine-Serine (GS) linkers (L5, L15 and L25). The Spike SmBiT sensors were made with 15aa, and 25aa GS linkers (S15 and S25). Because the N and C termini of the S-RBD domain locate in close proximity, only fusions to the C termini of S-RBD were constructed. f, The S sensors are most sensitive at 1 nM for detecting CR3022 in solution compared to higher or lower sensor concentrations. Two technical replicates are plotted from n=1 individual experiment. Lines connecting the means of the samples are plotted. g, S sensors with varied linker lengths resulted in very similar signal strength in detecting CR3022. Two technical replicates are plotted from n=1 individual experiment. Lines connecting the means of the samples are plotted.
